Field of the Invention
The present invention relates to a display device and a control method therefor in which a transparent display is used to which touch operations can be made from opposite sides thereof, i.e., a front face and a back face.
Description of the Related Art
Equipment using a transparent display has been put into practical use. With such equipment, light emitting devices such as organic electroluminescence diodes are formed on a transparent substrate, so that when an image is hidden, the transparent substrate becomes transparent, whereas when an image is displayed, such a display is carried out with the transparent substrate being made translucent. In addition, for the control of transparency, it is proposed that a plurality of liquid crystal shutter layers are superposed or stacked to form a transparent substrate, so that the transparency of the substrate is controlled according to the level or degree of opening and closing of each shutter (refer to Japanese patent application laid-open No. 2008-083510).
On the other hand, touch operation interfaces are becoming popular as user interfaces (UI) for display devices of portable terminals or personal digital assistants. In addition, there has been proposed a method of carrying out a touch operation from a back face of a display device, while looking at a front face thereof.
If a transparent display is used, an operation from a back face side can be seen from a front face side, a touch operation from the back face becomes easy. Thus, it is considered that with a portable terminal or personal digital assistant using a transparent display, a backside touch operation will become popular (refer to Japanese patent application laid-open No. 2007-334827).
Moreover, there has also been disclosed a technique in which in cases where a certain icon is pushed down, another icon associated with that icon is displayed in the vicinity thereof (refer to Japanese patent application laid-open No. 2003-209719).